Service providers may have the option to extend credit to customers for provided services with the expectation of payment at the termination of a service period. Alternatively, a service provider may require a customer to pay for services before they are provided. So-called prepaid services may allow a customer to purchase services prior to their provision and usage. Accordingly, a prepaid customer may maintain a positive monetary balance in a prepaid account held with the service provider. Alternatively, the customer may purchase units of service from the service provider for use over a period of time, In the example of a prepaid telecommunications service, a prepaid customer may purchase telecommunications services in units such as minutes.
Prepaid accounts may maintain a locked status while being used by a customer. Maintaining a locked status during the provision of service may simplify the call processing such that an account balance need not be divided among multiple simultaneous callers. However, in certain contexts, e.g., business customers and family calling plans, among others, it may be desirable to maintain a single prepaid account allowing multiple simultaneous callers to draw down the account balance.